A double-blind discontinuation study of clomipramine maintenance treatment in 20 obsessive compulsive adolescents found that 90% relapsed with desmethylimipramine substitution regardless of length of prior drug treatment. This suggests that indefinite drug maintenance may be indicated in Obsessive Compulsive Disorder (OCD) with existing therapies. A double-blind comparison of desipramine and clomipramine in 15 severe nail biters without other psychiatric disorder found clomipramine significantly superior in reducing nailbiting behavior. This extends the OCD spectrum concept to another "excess grooming" behavior (in company with trichotillomania and canine acral lick). A resting state 18FDG PET scan study of 10 women with trichotillomania and 20 matched normal controls found significantly higher brain global glucose metabolic rate for the trichotillomanic group, with bilateral cerebellar and left parietal regional normalized differences. First degree relatives of trichotillomanics had a significantly higher rate of OCD than a matched control group further supporting the relationship between trichotillomania and OCD. Fluoxetine was superior to fenfluramine in 10 dogs with canine acral lick., indirectly linking this naturally occurring canine grooming disorder to a mechanism similar to that seen in OCD.